Bone loss and pattern of destruction

2. Bone Loss
and
Pattern of Bone Destruction

3. Intruduction
• Equilibrium between bone resorbtion & formation
Level of bone past pathologic experience
Soft tissue of pocket wall present inflammation
condition
Degree of bone loss is free from pus
pocket depth
ulceration of pocket wall

4. Bone destruction caused by extension of
gingival inflammation
– Common cause of bone destruction
All Gingivitis periodontitis
Factors initiating conversion of
gingivitis to periodontitis are not known at this time

5. Bone destruction caused by extension of
gingival inflammation
Transition from gingivitis to periodontitis:
• Change in composition of bacterial plaque
 motile organisms and spirochetes increase
 coccoid rods and straight rods decreases
• Change in cellular composition of the infiltrated
connective tissue
Extention of inflammation to supporting periodontal
tissue modified by:
• Pathologic potential of plaque
• Resistance of host
The pathway of spread of inflammation is
critical in pattern of bone destruction

6. HISTOPATHOLOGY
Inflammation extending from gingiva to suprabony area
along blood vessels &between collagen bundles

7. HISTOPATHOLOGY
Extention of inflammation into the center of interdental
septum

8. Pathways of inflammation

9. Reformation of transseptal fibers

10. Extention of inflammation to crestal bone &
interdental septum

11. Osteoclasts & Howship lacunae in the
resorbtion of crestal bone

12. Tissues necrosis
And
pus Formation
occur in
soft tissue wall of pocket
not in
underlying bone

13. • The amount of inflammatory infiltrate
correlates with the degree of bone loss but
not with the number of osteoclasts.
• However, the distance from the apical
border of the inflammatory infiltrate to the
alveolar bone crest correlates with both
the number of osteoclasts on the alveolar
crest and the total number of osteoclasts.

14. Radius of action
• Page & Schroeder postulated a range of effectiveness of
about 1.5 to 2.5mm wihhin which bacterial plaque can
include bone loss.
• Presence of bacteria in the tissue caused defects
exceeding a distance of 2.5mm from tooth surfaces.

15. Rate of bone loss in 3 subgroups of patient
1.Rapid progression(yearly CAL=0.1-1mm)
2.Moderate progression(yearly CAL=0.05-0.5mm)
3.Minimal or no progression(yearly CAL=0.05-0.09mm)

16. Bursts of destructive activity are associated
with:
• Subgingival ulceration & acute inflammatory reaction
• T lymph → B lymph in lesion
• ↑loose,unattached,anaerobic,motile gram- flora
• Bacterial invasion followed by host defense

17. Mechanism of bone destruction
Factors involved are:
Bacteria inhibit action & number of osteoblasts+induce
diffrentiation of osteoclasts
Host produce factors made resorbtion
PGE2 NSAIDS
IL-1α
IL-1β
TNF-α

18. Bone formation in periodontal disease
• Buttressing bone formation
• Compensate the bone destroyed by inflammation
• Effect outcome of treatment

19. Basic aim of periodontal therapy:
Elimination of inflammation to remove
the stimulus for bone resorbtion &
allow the inherent constructive
tendencies to predominate

20. Bone destruction caused by trauma
from occlusion
• Without inflammation
• With inflammation

21. Bone destruction caused by systemic
disorders
• Magnify bone loss initiated by local inflammatory
process
• Its nature influence severity of periodontal destruction
• Periodontal bone loss & osteoporosis
• Generalized skeletal disturbances

22. Factors determining bone morphology in
periodontal disease
Normal variation in alveolar bone

23. Factors determining bone morphology in
periodontal disease
Exostoses
In rare cases develop after placement of free gingival graft

25. Factors determining bone morphology in
periodontal disease
TFO

26. Factors determining bone morphology in
periodontal disease
Butressing bone formation
•Central
•Peripheral

27. Factors determining bone morphology in
periodontal disease
Food impaction

28. Factors determining bone morphology in
periodontal disease
Aggressive periodontitis

30. Pattern of bone destruction
Horizontal bone loss
Most common pattern of bone loss

31. Pattern of bone destruction
Bone deformities(osseous defects)
Vertical bone loss

32. Intrabony pockets
always have
an underlying angular defect

33. Classification of angular defects

35. Combined osseous defects

36. Osseous crater

37. Bolbous bone contour

38. Reversed architecture

39. Ledges

40. Furcation involvement
• Invasion of furcation of multirooted teeth by periodontal
disease
• Mandibular first molars are the most common &maxillary
first premolars are the least common.
• Number of involvement increase with age
• Determined by exploration of a blunt probe
• has four grades
• Present no unique pathologic feature

45. Furcation involvement

46. Variation of destructive pattern in furcation
involvement

47. Predisposing factors
• Difficulty & Impossiblity of plaque control
• Proximity of the furcation to CEJ
• Trauma from occlusion
• Enamel projections
• Accessory pulpal canals

48. ‫ی‬‫و‬‫ر‬‫تره‬ ‫باال‬ ‫تو‬ ‫از‬ ‫پله‬ ‫یک‬ ‫خدا‬ ‫ی‬ ‫باش‬ ‫که‬ ‫ای‬ ‫پله‬ ‫هر‬
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